mm: do_sync_mapping_range integrity fix

Chris Mason notices do_sync_mapping_range didn't actually ask for data
integrity writeout.  Unfortunately, it is advertised as being usable for
data integrity operations.

This is a data integrity bug.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>